*: add git-reindent-branch.py

This tries to heave a branch over the reindentation step.  Somewhat
tested, don't trust it blindly...

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>

git-reindent-branch.py

@@ -0,0 +1,71 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+import sys, os
+import subprocess, argparse, tempfile
+import indent
+
+def run(cmd):
+    proc = subprocess.Popen(cmd, stdout = subprocess.PIPE)
+    rv = proc.communicate('')[0].decode('UTF-8')
+    proc.wait()
+    return rv
+
+argp = argparse.ArgumentParser(description = 'git whitespace-fixing tool')
+argp.add_argument('branch', metavar='BRANCH', type = str, nargs = '?', default = 'HEAD')
+args = argp.parse_args()
+
+branch = args.branch
+commit   = run(['git', 'rev-list', '-n', '1', branch, '--']).strip()
+beforeid = run(['git', 'rev-list', '-n', '1', 'reindent-master-before', '--']).strip()
+afterid  = run(['git', 'rev-list', '-n', '1', 'reindent-master-after', '--']).strip()
+
+beforebase = run(['git', 'merge-base', commit, beforeid]).strip()
+afterbase  = run(['git', 'merge-base', commit, afterid]).strip()
+
+if afterbase == afterid:
+    sys.stderr.write('this branch was already rebased\n')
+    sys.exit(1)
+
+if beforebase != beforeid:
+    sys.stderr.write('you need to rebase your branch onto the tag "reindent-master-before"\n')
+    sys.exit(1)
+
+revs = run(['git', 'rev-list', 'reindent-master-before..%s' % commit]).strip().split('\n')
+
+srcdir = os.getcwd()
+tmpdir = tempfile.mkdtemp('frrindent')
+os.chdir(tmpdir)
+
+sys.stderr.write('using temporary directory %s; %d revisions\n' % (tmpdir, len(revs)))
+run(['git', 'clone', '-s', '-b', 'reindent-master-after', srcdir, 'repo'])
+os.chdir('repo')
+
+prev = beforeid
+for rev in revs:
+    filestat = run(['git', 'diff', '-z', '--name-status', prev, rev]).rstrip('\0').split('\0')
+    changes = zip(filestat[0::2], filestat[1::2])
+    sys.stderr.write('%s: %d files\n' % (rev, len(changes)))
+
+    for typ, name in changes:
+        if typ == 'D':
+            run(['git', 'rm', name])
+        elif typ in ['A', 'M']:
+            run(['git', 'checkout', rev, '--', name])
+            if name.endswith('.c') or name.endswith('.h'):
+                for d in ['babeld/', 'ldpd/', 'nhrpd/']:
+                    if name.startswith(d):
+                        break
+                else:
+                    sys.stderr.write('\t%s\n' % name)
+                    indent.wrap_file(name)
+            run(['git', 'add', name])
+
+    run(['git', 'commit', '-C', rev])
+    prev = rev
+
+run(['git', 'push', 'origin', 'HEAD:refs/heads/reindented-branch'])
+sys.stderr.write('\n\n"reindented-branch" should now be OK.\n')
+sys.stderr.write('you could use "git reset --hard reindented-branch" to set your current branch to the reindented output\n')
+sys.stderr.write('\033[31;1mplease always double-check the output\033[m\n')
+